1. Field of the Invention
This invention relates to the protection of children within a public area having a surveillance perimeter, and more particularly concerns a system for detecting a child""s passage through said perimeter and providing appropriate alerting and countermeasures.
2. Description of the Prior Art
Many large retail stores have a multitude of long, high counters with intervening aisles, large displays, separate rooms, and a number of floors. A child can easily become lost in such environment, particularly amidst a multitude of shoppers. There is the further possibility that the child may become the victim of a kidnapper. Because the parent may be engrossed in the shopping activity, the fact that the child is missing may not be detected for a significant period of time, during which the child may, by virtue of wandering or abduction, be located far from the parent. Such concerns are also prevalent at other public facilities such as libraries, museums, theme parks, coliseums and stadiums.
Devices such as leashes have earlier been disclosed to facilitate the tethered connection of the parent to the child. However, such devices are impractical in the shopping center environment because of the close contact with people and store merchandising structures.
A child-locating bracelet which can be locked onto a child""s wrist is disclosed in U.S. Pat. No. 6,031,460 to Banks. The Banks bracelet employs a radio transmitter or a GPS system, thereby involving expensive, shock-sensitive components, and requiring the use of an included battery.
Electronic article surveillance (EAS) systems are well known for the prevention of shoplifting. Such systems generally involve the attachment of an alarm-triggering marker or security tag to an item of merchandise, and sensor means located adjacent the store entrance and/or exit A for detecting the tag. Examples of such tags are disclosed in U.S. Pat. Nos. 3,942,829; 3,995,900; 4,649,397; 4,686,516; 4,774,503; and elsewhere. One such surveillance system, as disclosed for example in U.S. Pat. No. 5,877,728, uses Radio Frequency (RF) based digital signal processing. When a xe2x80x9clivexe2x80x9d tag enters the sensor""s effective radio frequency detection field, an alarm is triggered that alerts personnel to a possible shoplifting attempt. The tag includes a resonant circuit that disrupts a radio frequency beam directed from a pedestal to a receiver located oppositely across the monitored pedestrian walkway.
For example, radio frequency EAS systems usually include both a transmit antenna and a receive antenna which collectively establish a surveillance zone, and tags which are attached to articles being protected. The transmit antenna generates a variable frequency electromagnetic field within a range of a first predetermined frequency. The resonant circuit of the tag is usually comprised of an antenna and diode, or antenna and capacitor, and has a predetermined resonant frequency. When one of the tags is present in the surveillance zone, the field generated by the transmit antenna induces a voltage in the resonant circuit in the tag, which causes the resonant circuit to generate an electromagnetic field, causing a disturbance in the field within the surveillance zone. The receive antenna detects the electromagnetic field disturbance and generates a signal indicating the presence of the tag (and thus, the protected article attached to the tag) in the surveillance zone.
A second type of electronic shoplifting surveillance system utilizes magnetic and acousto-magnetic merchandise tags for disrupting the signal from a sensor""s detection field. Such tags contain two pieces of thin metal that are caused to vibrate within the detection field. The vibration produces a disruptive frequency which interacts with a store exit detector.
Typically a magnetic system marker consists of a first elongated element of high magnetic permeability ferromagnetic material disposed adjacent to at least a second element of ferromagnetic material having higher coercivity than the first element. When subjected to an interrogation frequency of electromagnetic radiation, the marker causes harmonics of the interrogation frequency to be developed in the receiving coil. The detection of such harmonics indicates the presence of the marker.
A third type of EAS system employs magnetic harmonic markers which include a thin strip or wire of magnetic material that responds to an alternating interrogation signal by generating a signal pulse that is rich in high harmonics of the interrogation signal. Such markers are disclosed in U.S. Pat. No. 4,660,025 to Humphrey and U.S. Pat. No. 4,980,670 to Humphrey et. al.
A fourth type of EAS system employs magnetomechanical markers that include a magnetostrictive element. For example, U.S. Pat. No. 4,510,489, issued to Anderson et. al., discloses a marker formed of a ribbon-shaped length of a magnetostrictive amorphous material contained within a hollow recess in an elongated housing in proximity to a biasing magnetic element. The magnetostrictive element is fabricated such that it is mechanically resonant at a predetermined frequency when the biasing element has been magnetized to a certain level. At the interrogation zone, a suitable oscillator provides an AC magnetic field at the predetermined frequency, and the magnetostrictive-element mechanically resonates at this frequency upon exposure to the field when the biasing element has been magnetized to the aforementioned level. The resulting signal radiated by the magnetostrictive element is detected by detecting circuitry provided at the interrogation zone.
A fifth type of EAS system involves microwave activation.
EAS systems which use magnetomechanical markers have proved to be very effective and are in widespread use. Systems of this type are sold under the brand name xe2x80x9cUltra*Maxxe2x80x9d. In operating such systems, it is customary to attach magnetostrictive markers to the items of merchandise at retail stores which maintain equipment for generating the field for the interrogation zone. The attachment of the markers to the items of merchandise is typically carried out by means of a pressure sensitive adhesive layer provided on the marker, or, when the marker is intended to be removable, by a mechanical clamping device or the like. One example of such a device is disclosed in U.S. Pat. No. 5,031,756, issued to Buzzard et. al., which is directed to a xe2x80x9ckeeperxe2x80x9d which may be utilized in a retail store. The keeper includes a frame for holding a compact disk or similar item until the compact disk is paid for at a checkout counter. The keeper disclosed by Buzzard et. al. includes an EAS marker which may be a magnetomechanical marker of the type described in the Anderson et. al. patent.
U.S. Pat. No. 5,392,028 to Piche concerns a merchandise tag which incorporates two different kinds of EAS markers, namely the resonant circuit of the first above-mentioned system, and a magnetizable strip, as in the above-mentioned third system.
When a tag triggers an alarm at the exit site of the store, a procedure is activated which may include. the directed focusing of surveillance cameras and/or the alerting of security personnel.
In some of said shoplifting surveillance systems, the alarm tag can be removed by authorized store personnel using specialized devices, thereby enabling the customer to leave the store with the purchased merchandise. In other systems, the alarm tag is deactivated by magnetic or other principles instead of being removed. Such deactivation generally prevents reuse of the tag. It is also important to note that different stores may utilize various kinds of marker tags and detector systems.
Systems for electronically monitoring the whereabouts of children have been disclosed in U.S. Pat. Nos. 4,598,272; 4,598,275; 4,785,291; 5,689,240; 5,812,056; 5,841,352; 5,900,817, and elsewhere. In general, such devices either require continuous monitoring or involve conditions of use which are incompatible with a retail shopping center environment. The use of EAS tags on children has also been proposed. However, it should be noted that a shopping parent with a child may walk to a number of separate stores in a shopping center, each with its own distinctive EAS system.
It is accordingly an object of the present invention to provide a surveillance system for preventing the undesired passage of a child through the exit of a public facility.
It is another object of this invention to provide a system as in the foregoing object which utilizes a security tag compatible with exit detectors typically employed in EAS systems.
It is a further object of the present invention to provide a security tag useful in the system of the aforesaid nature which is attachable to the child as a locked protection bracelet.
It is still another object of this invention to provide a bracelet of the aforesaid nature capable of protectively holding any alarm activating security tag employed in current EAS systems.
It is an additional object of the present invention to provide a bracelet of the aforesaid nature of simple, durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.
The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a child protection bracelet of lightweight construction comprising:
1) a flexible band elongated upon a center axis between opposite first and second extremities and having a series of apertures disposed upon said axis adjacent said first extremity, said band having axially extending steel wires embedded therein,
2) a lock pin having a head extremity embedded within said band and a stem emergent from said head extremity and adapted to penetrate one of said apertures when said band is doubled upon itself in a circuitous path, and
3) a housing having a substantially flat bottom panel provided with a hole that receives said stem, and an upper shell portion sealed to said bottom panel, said housing protectively confining:
a) centrally located locking means for releasibly engaging said stem, and
b) EAS alarm-activating components.